# Identification and Management of a Novel Brown Spot Disease in Plums (Prunus salicina Lindl.)

## TL;DR

A new brown spot disease in plums caused by specific fungi was identified in China, and fluazinam was found to be the most effective treatment.

## Contribution

This is the first documentation of plum brown spot disease caused by Colletotrichum nymphaeae in China.

## Key findings

- The pathogens Colletotrichum nymphaeae, Fusarium sulawesiense, and Fusarium pernambucanum were identified as causes of the disease.
- Fluazinam was determined to be the most effective control agent against the disease.
- The study provides insights into the infection mechanisms and pathogenic characteristics of the identified fungi.

## Abstract

Plum (Prunus salicina Lindl.), belonging to the genus Prunus in the Rosaceae family, is one of the most widely cultivated deciduous fruit trees globally. Plums are renowned for their round, sweet fruits, which are rich in a variety of bioactive compounds and are deeply loved by consumers. However, in 2021, alarming reddish-brown–dark brown sunken lesions appeared on the fruits of Qingcui plums in Wanzhou, Chongqing, China. The pathogens were identified as Colletotrichum nymphaeae, Fusarium sulawesiense, and Fusarium pernambucanum. The present study further describes the growth patterns and pathogenic differences of these strains in different environments, elucidating their infection mechanisms and pathogenic characteristics; these findings provide a theoretical basis for the efficient management of plum brown spot disease. Additionally, we determined that fluazinam is the most effective control agent against the plum brown rot caused by these pathogens. Notably, this study is the first to document plum brown spot disease induced by C. nymphaeae in China. These findings are intended to provide a vital theoretical framework for the scientific management and control of plum brown spot; furthermore, they underscore the necessity of proactive prevention strategies in agricultural settings.